It’s pretty amazing what technology can do these days – from virtual mirrors to smart grocery stores to home assistants that answer our questions and play our favourite music. So it’s no surprise that L’Oreal’s new UV sensor is also pretty mind blowing.

Launched at the Consumer Electronics Show in Las Vegas, UV Sense, a first-of-its-kind sensor, is battery-free and absolutely tiny, at just 9mm in diameter and a thickness of 2mm. The sensor measures UV levels, and by communicating with a corresponding UV Sense app on your phone (iPhone and Android compatible, using the same technology used in contactless payment), can help you gauge where you are, and if you’re getting just a few too many rays.

For most of us, we notice the sun is too strong when we’re already getting burnt — which means it’s a little too late and some damage has already been done. Think about it — over a lifetime this could be some seriously useful information, helping to general lower UV exposure levels and help put you at a lower risk for skin cancer, so it’s way more than just ‘good-to-know’ info from a cosmetic device.

The sensor stores about 3 months’ worth of data, and can be worn on a fingernail or attached to your sunglasses, shoes or watch, so you don’t have to think about grabbing it on your way out the door. While you can put it wherever you like, L’Oreal suggests having it on your thumbnail, as its guaranteed to get a good amount of consistent sunlight.

Made in collaboration with Swiss design entrepreneur Yves Béhar, the sensor seems to be designed with both minimalism and functionality in mind, looking sleekly discreet. You can check out more about L’Oreal’s thought and design process:

To get your hands on one yourself, you’ll have to be a bit patient as they’ll be available only via dermatologists for the next year or so, after which they’ll released to the public. And the best thing? When they are, they’ll be $50 or less — a small price to pay for taking care of your skin.